Is there something going on out there? (or Getting Back to My Roots...)



#2

Hi, all;

After having my newest HP50g being ‘eaten’ to its guts by one leaking battery from the four standard ones that came with the calculator while resting for about a month, I decided to buy a new one and actually grabbed it a few hours ago. Strangely the calculator’s blister was a bit thinner than the other ones and, after a first look, I noticed that the printed manual was replaced by a printed, 54-page 'Quick Start Guide', a black-and-white cover brochure (Mine is Edition 2, part # F2229-90201, no month-year stamp). What actually called my attention was a (very good) surprising change: when applicable, all examples from page #5 and ahead are illustrated with the calculator in RPN mode. Page #5 particularly has the following words under ‘Using RPN’:

Quote:
The HP50g comes from a history of calculators designed specifically for engineers an mathematicians. (...) Because the HP50g comes from a line of calculators that used RPN exclusively, the calculator is easier to use and functions most effectively in RPN mode.

Maybe some of you have not noticed that, but I could not help mentioning it here. Any chance that someone at HP H.Q. wants to get the company back to its roots? I mean, to give credit to whatever deserves? RPN was first use in calculators by HP, and it has been neglected since the new manuals for the new calculators with both systems (HP17BII/BII+, HP49G/50G, etc) only mentions RPN as 'the other operating mode', and almost all of the examples (if not all of them) in these manuals are performed by using the calculator in algebraic mode. And without no intention of turn the flames on again (even knowing it may happen...), I still believe that RPN as a calculating mode helps reasoning on and understanding the solution instead of trying to rely on the number in the display after pressing the [=] key...

Cheers.

Luiz (Brazil)


#3

I think I read here that TW had something to do with that :-)


#4

Yes a 54 page "Quick Start Guide" sounds suspiciously like Tim's document.

Great job Tim!


#5

Yup. I wrote it. After it was done and ready to go, I was informed we could add a few more pages. You can probably easily spot where it switches from me to a technical writer filling in a bit more info.

Everyone agrees that using the 50g in alg mode is kind of clunky, so I wanted to try and get people at least exposed. I don't care if they want to use algebraic, but hopefully they will see they can use algebraic in RPN and not lose the benefits. Also, I knew right away there was no possible way both modes could be covered, and since using algebraics in RPN is easy on an RPL machine, I figured I could stick it in that way. I think I even devoted a section to "Using Alegebraics in RPN" or something like that.

It was approached from the "there is far too much to teach here, so let's try to expose as many simple, cool things that make people appreciate the new calculator, and hopefully get over that initial hurdle in using it." By the end, I hope people can at least use it for basic calculations and equation solving without feeling too lost.

Some places are exteeeeeemly dense in information. I remember writing a few sentences in a row that introduce 2 or 3 things in each sentence. I hope people will actually sit down and go through it once or twice. I still discover things about the 50 I wish I'd know a few years ago every now and again. :-)

TW

PS - as I hope I will be able to write more of these in the future, feel free to send any comments (positive/negative) so I can hopefully continue to improve.

Edited: 27 Apr 2010, 1:08 a.m.


#6

Quote:
I still discover things about the 50 I wish I'd know a few years ago every now and again. :-)

Tim,

Speaking of which, did you see the bug I found where FACTORS thinks that 9999999967^2 is prime? (In version 2.09 of the firmware.) I did a bit more checking and it seems that squares of primes that are 10 digits in length or larger are not factored correctly. (2^31 - 1)^2 is another example. However, in all cases ISPRIME? works correctly.

-Katie

#7

Any chance this quick start guide is available as a pdf online?

Thanks


#8

As an owner of an HP50g standing in front of that hurdle I'd like to queue for such an pdf as well. TIA


#9

ftp://hp50gqsg:Crooned2@ftp.usa.hp.com/

Here is a temporary FTP. Just click the link and almost all browsers will open for you to download. It will be active for about 30 days or so. I am not sure if the QSG documents will ever be online for individual download. . .

TW

Edited: 27 Apr 2010, 6:45 p.m.


#10

Thanks Tim! :)

#11

Thank you Tim d:-)

#12

Hi Tim,

Would it be possible to put it on hpcalc.org?

#13

Tim, great work! Thank you for sharing it with us.

#14

Hi, Tim;

thank you, too! After seeing the PDF I noticed that the time stamp exist at page iv, under printing history.

Great job!

Cheers.

Luiz (Brazil)

Edited: 28 Apr 2010, 9:57 a.m.

#15

Tim. Thank a bunch. I'm not half way through and I already know much more about my calculator than I did yesterday. :-)

#16

Hi, Luiz!!

This may be obvious for many of you, but it's news for me: Does the 50G has a RPN-mode (with a four-level stack, copy of "T" on drop, etc.), or it's just RPL like the 48G and siblings? A RPN (I mean, with a final "N") mode would be a very nice thing! On the other hand, for my old brain, RPL and algebraic are both an effort to work with.


Edited: 26 Apr 2010, 8:02 a.m.


#17

I think that the old RPN is dead at HP. The 20b and 30b are advertised as 'RPN' calculators and indeed have a 4-level stack with t copied to z on drop, but they don't push x into y until you perform another entry. This means that you can't do something like "5 ENTER *" as a way to get 5 squared. This is how RPL works but is really the only change from the traditional RPN.

-Katie


#18

I re-learned (or remembered perhaps?) a few things about RPN while writing the 41Z module - all relative to that automated stack lift and no need for argument re-entry. It´s funny how we take all that for granted until you need to replicate the way it works on a complex memory buffer...


Edited: 27 Apr 2010, 12:52 p.m.

#19

Ola, Andrés; ¿como estás?

You are correct: the HP50G is actually an RPL-based calculator. And it has no RPN-like functionality, as it happens with the actual RPN-based models (HP35, HP41, HP42, HP19BII, etc.). Fact is that the HP50G 'Quick Reference Manual' mentions RPN as the main operating mode while previous literature mentions RPN as 'the other operating mode'. That is what called my attention.

I actually did not notice the RPN<->RPL 'reversal' reference, if I can say so...

Cheers! (long time no... read, Andrés!)

Luiz (Brazil)


#20

Quote:
You are correct: the HP50G is actually an RPL-based calculator. And it has no RPN-like functionality, ...

I think this distinction, apparently so obvious to most members here, might be lost on the general universe of calculator users, including myself.

In other words, the math logic used for entering problem is definitely RPN-like to me, at least as compared to algebraic logic ...


#21

Hi,Martin;

as a matter of fact, I remember that some discussion arose when the meaning of RPL became the subject here, some long time ago. I must confess I am not aware of what does actually RPL stand for. At wikipedia we find:

Quote:
The RPL programming language (RPL meaning ROM-based procedural language following Hewlett-Packard or, alternatively, Reverse Polish LISP) is a handheld calculator system and application programming language used on Hewlett-Packard's engineering graphing RPN calculators of the HP-28, HP-48, HP-49 and HP-50 series, but it is also usable on non-RPN calculators, such as the HP-39 series.

Cheers.

Luiz


#22

Luiz, as I see it, if the hallmark of RPN is postfix notation, then the RPL machines are the most RPN-like of all, since in them everything is postfix, even operations like setting the number of decimal spaces in FIX mode.

However, I take it that the definition of RPN being used by the RPN aficionados here is the type of operation used by the certain traditional HP machines, which is really a combination of prefix and postfix.


#23

Hi Martin.

I think you are correct.

But the infix part is very few commands, most notably STO - [reg], RCL + [reg], FIX [value], SF [n] and their relatives.

As I see it, there isn't any mathematical operation in "traditional" RPN other than the storage arithmetic.

#24

Hi, Martin;

Quote:
(about RPN) the type of operation used by the certain traditional HP machines, which is really a combination of prefix and postfix.
I always applied the 'postfix notation' reference to the calculator core, I mean, math and arithmetic operations. If we consider algebraic notation, RPN is homogeneous in terms of math and arithmetic operations. In calculators operating with algebraic notation we have either postfixed (e.g.: 45 COS for COS(45), no need for [=] key) or infixed operation (e.g. 4 + 5 [=]) or, in some newer machines, prefixed operations (e.g.: [COS] 45 [=]; in these machines, COS( appears in the display when [COS] is pressed). Because algebric notation allows such distinctive keystroke sequences without loosing algebraic correspondence, chances are that RPN-based calculators have easier, simpler rules to be remembered.

All of the rest, namely structural operations like FIX, STO & RCL, program-addressed operations like LBL, GTO and GSB and others, are essentially prefixed in the early RPN models. With the HP67/97 the indexed -or indirect- addressing allowed prefixed operations to behave like postfixed operations.

But I guess all of this is mainly known, it is just a matter of putting things together. When the HP28C was introduced, two particular chapters in its Owner´s Manual deal with that: Notes for Algebraic Calculator Users and its counterpart for RPN, too. The softbound, thick HP48 Owner´s manual also brings a dedicated appendix: Comparing the HP 48 and HP 41. The PDF file in the link was created over scanned images of the original HP48 manual. Page #3 in this PDF (page #F6 in the original manual) has a very concise explanation about these differences.

Also, we must notice that Willian C. Wickes 'Insights' books are 'THE' source of information for these matters, if I may.

Well, I see I wrote too much, sorry! Chances are that users with the need of extra clarification may find in these texts some guidance. And I hope my writings will not get readers into confusion...

Cheers.

Luiz (Brazil)


Edited: 26 Apr 2010, 10:00 p.m.


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